For the syrup water, you can use any type of filtered water is fine, but if you have RO it would be better and cleaner.
The thing with RO is that most non-commercial models can produce around 50 gallons a day, which in some cases may be insufficient. Commercial models are very pricey and usually not practical for smaller businesses. Depending on how much water you plan to use, sometimes it might be worth it to purchase water from a water store. In california, RO water only cost around $2-3 for a 5 gallon jug which would be more than enough for regular operations. If you don't have cheap commercial water in your area, you could buy small RO units for around $200 some dollars. Here is a site that we normally go to when we replace our filters :
http://www.waterfilters.net/I believe they have a RO unit for around $250 and has a capacity of 50 gallons.